Draw rollers, whose pull rings arranged laterally are to run in the unprinted margin area of the web, are used to convey a web, e.g., a printed paper web in a folder of a rotary printing press. Two rollers coupled by a drive with two pull rings each, which are in functional connection with one another in pairs and ensure the pulling of the web and consequently the conveying of the web by a rotary movement, are usually provided.
If webs of different widths, e.g., different paper widths for different formats of printed products, are to be used, the draw roller with the pull rings arranged thereon must be adapted correspondingly.
A roller with pull rings is known from EP 0 140 015 A2, where a set of semicylindrical inserts is removed and replaced with another set of semicylindrical inserts, at which the pull rings are arranged in different positions to change the position of a pull ring. The clamped inserts must be removed for this purpose from the jacket surface of the draw roller and new inserts must be clamped. According to EP 0 140 015 A2, the time hitherto needed for correspondingly changing the roller can thus be reduced from about one day to about 15 minutes.